This is my very first post, so am starting with my favorite subject Hematology.
Today's post is about Immunohemolytic anemias, commonly ignored type of anemia
Also referred as Autoimmune hemolytic anemias(AIHA)
Where antibodies are responsible for premature destruction of red blood cell.
Types- warm antibody type
- cold agglutinin type
- cold hemolysin type
Warm antibody type - It is the most common type of AIHA.
you can remember it by mnemonic
" WARM GRILLED "
W - Warm because, antibodies are active
A - Associated with other Autoimmune
disorders ( secondary causes like
R - Red cell hemolysis is mainly
M- Moderate spleenomegaly due to
hyperplasia of splenic phagocytes
G- Ig G class - most common causative
antibodies ( IgA sometimes too)
R- Rh blood group antigens are the main
I- 50% primary cases are Idiopathic
Secondary causes can be
L- Lymphoid neoplasm
ED- Exposure to Drugs.
Examples - penicillin, cephalosporins, quinidine, methyl dopa etc
Mechanism - A) Antigenic drugs-
Drugs such as penicillin binds to red cell membrane and they are recognized by the antidrug antibody. The antibody either recognizes the drug and bind to it or both drug and membrane protein,ultimately results in hemolysis.
B) Tolerance breaking drugs- In drugs such as methyl dopa, antibodies are formed against red cell antigens particularly Rh antigens.